Intermittent micro-aeration : New strategy to control volatile fatty acid accumulation in high organic loading anaerobic digestion

Copyright © 2019 Elsevier Ltd. All rights reserved..

This study developed an intermittent oxidation-reduction potential (ORP)-controlled micro-aeration system for high solids anaerobic digestion (AD) of lignocellulosic biomass without volatile fatty acids (VFA) accumulation at high organic loading rate (OLR). Traditional AD of Napier grass, a model lignocellulosic biomass, at an OLR of 5 g volatile solids (VS)/L/day resulted in an accumulation of total VFA concentration up to 9.2 g/L as acetic acid (HAc) equivalent, causing rapid drops in pH and methane yield, and driving the digester to the verge of failure. Once intermittent (every 24 h) ORP-controlled micro-aeration (at ORP of -470 mV) was initiated, the total VFA concentration rapidly decreased to 3.0 g HAc/L and the methane yield improved, resulting in stable digester performance without the need for alkalinity supplementation or OLR reduction. By combining reactor performance results, mass balance analyses, microbial community characterization data, and a bioenergetic evaluation, this study suggested that rapid VFA conversion and CH4 production were carried out by facultative anaerobes and hydrogenotrophic methanogens under micro-aerobic conditions. This novel operating approach can be applied as an effective control strategy for high OLR AD processes especially in the event of VFA accumulation.

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:166

Enthalten in:

Water research - 166(2019) vom: 01. Dez., Seite 115080

Sprache:

Englisch

Beteiligte Personen:

Nguyen, Duc [VerfasserIn]
Wu, Zhuoying [VerfasserIn]
Shrestha, Shilva [VerfasserIn]
Lee, Po-Heng [VerfasserIn]
Raskin, Lutgarde [VerfasserIn]
Khanal, Samir Kumar [VerfasserIn]

Links:

Volltext

Themen:

Anaerobic digestion
Fatty Acids, Volatile
Journal Article
Metabolic pathway
Methane
Micro-aeration
Microbial community
OP0UW79H66
Oxidation-reduction potential (ORP)
VFA accumulation

Anmerkungen:

Date Completed 25.11.2019

Date Revised 25.11.2019

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.watres.2019.115080

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM301497710